ABSTRACT
AIM: The aim of this study was to compare 99mTc-MIBI brain SPECT and proton magnetic resonance spectroscopy (1H-MRS) findings and to evaluate their association. METHODS: Both exams were performed on 30 glioma patients, previously operated and treated with radiotherapy, having MRI doubtful between recurrence and radiotherapy effects. SPECT images were acquired 15 minutes after radiopharmaceutical administration with a dual-head gamma camera. T1/B1 uptake ratio was calculated between a tumor ROI (T1) and a normal mirror symmetric ROI (B1) and T2/B2 ratio was obtained between a ROI in the hottest neoplastic part (T2) and a normal mirror symmetric ROI (B2). 1H-MRS was performed using a 1.5 T system equipped with a spectroscopy package. SPECT and 1H-MRS data were compared with histology after new surgery or with follow-up. RESULTS: SPECT and 1H-MRS showed recurrence in 18 patients (confirmed by biopsy, coinciding only in 17 cases) and were negative in 10 (1 false negative). SPECT and 1H-MRS disagreed in 2 cases of recurrence (1 diagnosed by brain SPECT, 1 by 1H-MRS). T1/B1 ratio mean value (4.26+/-2.5) was significantly lower than T2/B2 (4.93+/-2.81; P<0.001). SPECT and 1H-MRS sensitivity in detecting recurrence was 90%, specificity 100%, accuracy 93%, negative predictive value (NPV) 83% and positive predictive value (PPV) 100%; the associated exams sensitivity was 95%, specificity 100%, accuracy 96.6%, NPV 90.9%, PPV 100%. CONCLUSIONS: Brain SPECT and 1H-MRS have equivalent values of diagnostic parameters in differentiating tumor recurrence and radiation effects, and their association might provide additional information.
Subject(s)
Brain Neoplasms/diagnosis , Brain Neoplasms/radiotherapy , Glioma/metabolism , Glioma/radiotherapy , Magnetic Resonance Spectroscopy/methods , Neoplasm Recurrence, Local/diagnosis , Technetium Tc 99m Sestamibi , Adult , Aged , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/prevention & control , Prognosis , Protons , Radiopharmaceuticals , Statistics as Topic , Tomography, Emission-Computed, Single-Photon/methods , Treatment OutcomeABSTRACT
From 1990 to 1997, 16 consecutive patients with stage III and IVa invasive thymoma were treated in a single institution with primary chemotherapy consisting in adriamycin (40 mg m(-2)), cisplatin (50 mg m(-2)) administered intravenously on day 1, vincristine (0.6 mg m(-2)) on day 2 and cyclophosphamide (700 mg m(-2)) on day 4 (ADOC). The courses were repeated every 3 weeks. The aim was to evaluate the impact of this cytotoxic regimen with respect to response rate, per cent of patients radically resected, time to progression and overall survival. Two complete responses (one clinical and one pathological) and 11 partial responses were observed (overall response rate 81.2%); two patients had stable disease and one progressed. Toxicity was mild as only two patients developed grade III/IV neutropenia and one patient grade III nausea/vomiting. Nine patients were radically resected (five out of ten with stage III, and four out of six with stage IVa). Median time to progression and overall survival was 33.2 and 47.5 months respectively. Three patients were alive and disease free after more than 5 years. The ADOC scheme is highly active and manageable in the treatment of locally advanced thymoma. As a preoperative approach it should be offered to patients not amenable to surgery or to those surgically resectable but with a great deal of morbidity.
